Method and apparatus for block acknowledgement in a communication network

ABSTRACT

A method includes receiving a request for bandwidth from a first network node of a coordinated network and broadcasting a first transmission schedule to a plurality of network nodes including the first network node. The first transmission schedule allocates bandwidth for the first network node to transmit data to a second network node. An acknowledgement (ACK) message is received from the second network node identifying that the second network node successfully received the data from the first network node.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/145,327, which was filed on Jan. 16, 2009, the entirety of whichis incorporated by reference herein.

FIELD OF DISCLOSURE

The disclosed methods and apparatus relate to data transmission. Morespecifically, the disclosed methods relate to data transmission incoordinated networks.

BACKGROUND

Many communication systems include an automatic repeat request (ARQ)error controlling method to ensure data is successfully transmitted fromone network node to another. For example, in a “stop and wait” ARQ, atransmitting node transmits a first data packet to a receiving node andthen waits until it receives an acknowledgement (ACK) message from thereceiving node identifying that the receiving node has successfullyreceived the first data packet. The transmitting node sends a seconddata packet once it receives the ACK message from the receiving node. Ifthe transmitting node does not receive an ACK message from the receivingnode within a predetermined period of time, then the transmitting nodewill retransmit the first data packet to the receiving node and wait toreceiving an ACK message. In some ARQ methods, a negative ACK (NACK orNAK) message is transmitted from the receiving node to the transmittingnode if a data packet is not successfully received.

In coordinated networks, e.g., a communication network in which datatransmission is scheduled by one of the network nodes referred to as aNetwork Coordinator (“NC”), the transmission of the ACK or NACK messagesfrom the receiving node to the transmitting node are scheduled by theNC. Accordingly, although the ARQ methods improve the reliability ofdata transmission by notifying the transmitting node that a data packethas not been properly received, such methods also impose latency andjitter issues as well as sometimes requiring packet reordering.Additionally, ARQ methods require memory for storing packets in thetransmitting nodes that may have to retransmit a packet in addition torequiring system bandwidth in order to retransmit the unsuccessfullyreceived data packet.

SUMMARY

An apparatus and method are disclosed that includes receiving a requestfor bandwidth from a first network node of a coordinated network andbroadcasting a first transmission schedule to a plurality of networknodes including the first network node. The first transmission scheduleallocates bandwidth for the first network node to transmit data to asecond network node. An acknowledgement (ACK) message is received fromthe second network node identifying that the second network nodesuccessfully received the data from the first network node.

Another apparatus and method are disclosed in which a request forbandwidth is transmitted to a network controller of a coordinatednetwork. The request for bandwidth is for transmitting data to a firstnode. A first transmission schedule for each of a plurality of networknodes in the coordinated network is received from the networkcoordinator. The first transmission schedule allocates bandwidth fortransmitting the data to the first network node. The data is transmittedto the first network node in the allocated bandwidth in accordance withthe first transmission schedule.

Also disclosed are an apparatus and a method in which a firsttransmission schedule for each of a plurality of network nodes in acoordinated network is received from a network coordinator. The firsttransmission schedule allocates bandwidth for receiving data from afirst network node. The data is received from the first network node inaccordance with the first transmission schedule, and an acknowledgement(ACK) message is transmitted to the network coordinator if the data issuccessfully received from the first network node.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one example of a coordinated network.

FIG. 2 is a block diagram of one example of a network node in accordancewith the coordinated network illustrated in FIG. 1.

FIG. 3 is a timing diagram of a conventional data transmissionacknowledgement methodology in a coordinated system of the PRIOR ART.

FIG. 4 is a timing diagram of an improved data transmissionacknowledgement methodology in a coordinated system.

FIG. 5 is a flow diagram of one example of a method of acknowledgingdata transmission performed by a network coordinator in a coordinatednetwork.

FIG. 6 is a flow diagram of one example of a method of acknowledgingdata transmission performing by a transmitting network node in acoordinated network.

FIG. 7 is a flow diagram of one example of a method of acknowledgingdata transmission performed by a receiving network node in a coordinatednetwork.

DETAILED DESCRIPTION

The improved methods and apparatus for acknowledging data transmissionin a coordinated network are described with reference to a Multimediaover Coaxial Alliance (MoCA) network. However, one skilled in the artwill understand that the disclosed apparatus and methods are not limitedto MoCA networks, but may be implemented in a wide variety ofcoordinated networks in which data transmission is scheduled by one ofthe network nodes.

FIG. 1 is a block diagram of one example of a coordinated network 100.As shown in FIG. 1, a plurality of network nodes 104-1:104-5(collectively referred to as “network nodes 104”) may be communicativelycoupled to each other through communication medium 102. Although fivenetwork nodes are shown in FIG. 1, one skilled in the art willunderstand that fewer or more nodes may be coupled to each other throughcommunication medium 102 to form a coordinated network. The networknodes 104 may be devices of a home entertainment system such as, forexample, set top boxes (STBs), television (TVs), computers, DVD orBlu-ray players, gaming consoles, to name a few, each coupled to eachother via the communication medium 102. Examples of the communicationmedium 102 include, but are not limited to, coaxial cable, fiber opticcable, a wireless transmission medium, and an Ethernet connection, toname a few.

FIG. 2 illustrates a simplified block diagram of one example of anetwork node 104. As shown in FIG. 2, network node 104 may include aphysical interface 110 including a transmitter 112 and a receiver 114,which are in data communication with a processor 106 through a data bus116 as illustrated in FIG. 2. The transmitter 112 may include amodulator 118 for modulating data onto a plurality of orthogonalfrequency division multiplexed (OFDM) subcarriers according to aquadrature amplitude modulation (QAM) scheme such as, for example,8-QAM, 16-QAM, 32-QAM, 64-QAM, 128-QAM, or 256-QAM, and adigital-to-analog converter (DAC) 120 for transmitting modulated signalsto other network nodes 104 through the communication medium 102.

Receiver 114 may include an analog-to-digital converter (ADC) 122 forconverting a modulated analog signal received from another network node104 into a digital signal. Receiver 114 may also include an automaticgain control (AGC) circuit 124 for adjusting the gain of the receiver114 to properly receive the incoming signal and a demodulator 126 fordemodulating the received signal. One skilled in the art will understandthat the network nodes 104 may include additional circuitry andfunctional elements not described herein.

Processor 106 may be any central processing unit (CPU), microprocessor,micro-controller, or computational device or circuit for executinginstructions. As shown in FIG. 2, the processor 106 is in signalcommunication with a computer readable storage medium 108 through databus 116. The computer readable storage medium may include a randomaccess memory (RAM) and/or a more persistent memory such as a read onlymemory (ROM). Examples of RAM include, but are not limited to, staticrandom-access memory (SRAM), or dynamic random-access memory (DRAM). AROM may be implemented as a programmable read-only memory (PROM), anerasable programmable read-only memory (EPROM), an electrically erasableprogrammable read-only memory (EEPROM), or like device configured tostore data and instructions that may be executed by the processor 106 aswill be understood by one skilled in the art.

In a Multimedia Over Coaxial Alliance (MoCA) network, data packets aretransmitted over a coaxial communication channel and the communicationbetween network nodes 104 is managed by a Network Coordinator (NC) node.The NC may be any of the plurality of network nodes 104 and may switchfrom node to node over time as network nodes join and/or leave thenetwork. The NC periodically broadcasts Beacons and Media Access Plan(MAP) packets to the nodes connected to the network. The Beacons aretransmitted at regular intervals (e.g., every 10 ms) and identify thechannel time clock (CTC), the MoCA network version, the time of the nextadmission control frame (ACF), and when a NC handoff will occur (e.g.,when the NC changes from one network node to another network node). MAPpackets are transmitted more frequently by the NC than are Beacons andprovide scheduling information that identify when each network node willbe transmitting data through the network. The NC may receive reservationrequests from each of the plurality of network nodes 104 between MAPpacket transmissions in which each of the network nodes 104 report theirtransmission capabilities and request to transmit data to other networknodes.

FIG. 3 is one example of a timing diagram for setting up a data flow ina conventional MoCA network. As shown in FIG. 3, bandwidth reservationrequests are transmitted to the NC, which in this example is networknode 104-4, from network nodes 104-1, 104-2, and 104-3. NC 104-4broadcasts a MAP packet to each of the network nodes 104-1:104-3. TheMAP packet may identify the transmission schedule including thebandwidth allocated to each of the plurality of nodes 104 in thenetwork.

After the MAP is received by each of the network nodes 104-1:104-3, datatransmission begins with node 104-1 transmitting data to node 104-2,node 104-2 transmitting data to node 104-3, the NC 104-4 transmittingdata to node 104-2, and node 104-2 transmitting data to node 104-1. Eachdata transmission is successful except for the data transmission fromnode 104-1 to node 104-2. Accordingly, an acknowledgement (ACK) messageis transmitted from node 104-3 to node 104-2, from node 104-2 to NC104-4, and from node 104-1 to node 104-2, and a negative ACK (NACK)message is transmitted from node 104-2 to node 104-1.

Next, reservation requests from nodes 104-1:104-3 are transmitted to NC104-1 with only node 104-1 requesting bandwidth in order to retransmitthe data to node 104-2. NC 104-4 transmits the next MAP packet in whichthe bandwidth for retransmitting data is reallocated for node 104-1 totransmit data to node 104-2. After the MAP is received by each of thenodes 104-1:104-3, data transmission begins and node 104-1 retransmitsthe data to node 104-2. Node 104-2 transmits an ACK message uponsuccessfully receiving the data from node 104-1.

The conventional acknowledgement method described above requires networkbandwidth for not only retransmitting the data from the transmittingnode to the receiving node, but also for the transmitting node totransmit an ACK or NACK message to the transmitting network node, whichin turn transmits a request for bandwidth to the NC for retransmittingthe data to the receiving node. Additionally, the transmitting networknode will then wait until a MAP packet is received that allocatesbandwidth for the retransmission of the data, which induces packetlatency and jitter.

FIG. 4 is one example of a timing diagram of an improved method ofacknowledging data transmission in a coordinated network. As shown inFIG. 4, bandwidth reservation requests are transmitted from networknodes 104-1:104-3 to NC 104-4. NC 104-4 receives the reservationrequests from network nodes 104-1:104-3 and determines a transmissionschedule. The reservation requests may identify the type of datatransmission, e.g., the quality of service required, the availableresources of the network node that transmitted the service request, thedata size that is to be transmitted by the network node, and theidentity of the network nodes that are to be receiving the datatransmission. The transmission schedule generated by NC 104-4, which maybe based on the data received in the reservation requests from each ofthe network nodes 104-1:104-3, may allocate the bandwidth and/ortransmission time or time slot at which a network node is to transmitdata. The transmission schedule may be transmitted to each of thenetwork nodes 104 as a MAP packet.

Network nodes 104 transmit data after receiving the first MAP packet.For example, node 104-1 transmits data to node 104-2, node 104-2transmits data to node 104-3, NC 104-4 transmits data to node 104-2, andnode 104-2 transmits data to node 104-1. As shown in FIG. 4, the node104-2 does not successfully receive the data transmitted from node104-1.

Instead of each of the receiving nodes transmitting an ACK or NACKmessage to the network node for each packet it was scheduled to receive,the ACK and NACK messages are aggregated into a single message anddirectly transmitted to NC 104-4. One skilled in the art will understandthat there are numerous methods through which the ACK and NACK messagesmay be transmitted directly to the NC. In one implementation, forexample, NC 104-4 may schedule an “ACK slot” for each of the networknodes scheduled to receive a data packet. Accordingly, a MAP packet mayassign bandwidth and/or a time slot in which each of the network nodesscheduled to receive a data packet in the MAP packet is scheduled totransmit an ACK or NACK message to the NC. In another implementation,the receiving network nodes transmit their respective ACK or NACKmessages to the NC 104-4 using orthogonal frequency division multipleaccess (OFDMA). For example, each of the receiving nodes may be assigneda unique set of sub-carriers to signal an ACK or NACK. The sub-carrierassignments may be determined by the NC 104-4 and reported to thenetwork nodes 104 in the same MAP packet that includes the datatransmission schedule. In yet another implementation, the receivingnetwork nodes piggyback the ACK or NACK messages to another packetalready scheduled for transmission to the NC 104-4. For example, each ofthe receiving nodes may piggyback the ACK and NACK messages toreservation requests. In yet another implementation, the receivingnetwork nodes transmit their respective ACK or NACK messages using codedivision multiple access (CDMA). CDMA reporting may be implemented in asimilar manner as OFDMA described above, except that unique spreadingcodes instead of unique sub-carriers would be included in the MAPpackets broadcast by the NC 104-4. One skilled in the art willunderstand that other techniques may be implemented for transmittingacknowledgement messages to the NC.

Referring again to FIG. 4, each of the network nodes 104-1:104-3 maytransmit reservation requests to NC 104-4 once the ACK and/or NACKmessages have been transmitted. In some embodiments, the reservationrequests may be omitted or they may include the ACK or NACK messages.Having received the ACK and/or NACK messages and the reservationrequests from each of the network nodes 104-1:104-3, NC 104-4 determinesa second transmission schedule, which may be based on the data reportedin the reservation request messages received from the network nodes 104as described above. The second transmission schedule, which includesreallocated bandwidth for network node 104-1 for retransmitting data tonetwork node 104-2, is transmitted to each of the nodes as a MAP packet.Network node 104-1 then retransmits the data to network node 104-2 inthe reallocated bandwidth.

FIG. 5 is one example of a flow diagram of a method of acknowledgingdata transmission that may be performed by a NC. As described above,each of the network nodes may be configured to perform the functions ofthe network coordinator. As shown in FIG. 5, the NC receives areservation request to transfer data from a first node to a second nodeat block 502. One skilled in the art will understand that the NC mayreceive a plurality of reservation requests from a plurality of networknodes. For example, the NC may receive a request from one node totransmit data to a plurality of network nodes (i.e., multicasttransmission) and may receive a second request from a different networknode to send data to another network node (i.e., unicast transmission).

At block 504, the NC determines a transmission schedule based on thereservation requests. The transmission schedule may identify bandwidthand/or transmission times for all network data transmission for the nexttransmission period between MAP packets. The transmission schedule,including the number of data flows, transmitting and receiving nodesassociated with each data transmission, the required resourcesassociated with each data transmission, and the size of the data beingtransmitted, may be stored by the NC in a computer readable storagemedium for subsequent use.

The transmission schedule is broadcast to each of the network nodes as aMAP packet at block 508. At decision block 510, the NC determines whichtype of acknowledgment message has been received from the receivingnetwork node. If a NACK message is received by the NC, then the NCproceeds to block 504 to reallocate the bandwidth for the datatransmission from the first node to the second node in a subsequenttransmission schedule. In reallocating the bandwidth and the networkresources for the data transmission, the NC may retrieve the dataassociated with the data transmission from the first node to the secondnode stored at block 506 from the computer readable storage medium anduse this data in developing the subsequent transmission schedule.Storing the transmission data from the previous transmission schedule atthe NC advantageously enables the NC to recall the requested bandwidthand the identities of the transmitting and receiving nodes withoutrequiring the transmitting node to resubmit a reservation request, whichin turn reduces packet latency and increases bandwidth and throughput inthe communication network. The NC broadcasts the subsequent transmissionschedule with the reallocated bandwidth as a MAP packet to each of theplurality of network nodes.

If the NC receives an ACK message, then it may proceed to block 512where the data transmission is completed and the data from thepreviously transmitted transmission schedule is erased from the computerreadable storage medium. As will be understood by one skilled in theart, the NC may then continue to block 502 and receive reservationrequests from each of the plurality of network nodes for setting up newdata transmission flows in the coordinated network.

FIG. 6 is one example of a flow diagram for a method of acknowledgingdata transmission that may be performed by a transmitting network node.As shown in FIG. 6, the transmitting network node transmits a requestfor bandwidth to transmit data to a network node to the NC. Thebandwidth request may be included in the reservation request messagethat each network node may periodically transmit to the NC.

At block 604, the transmitting node receives the transmission schedulefrom the NC. As described above, the transmission schedule may be a MAPpacket including allocated bandwidth and/or allocated time slot in whichthe transmitting network node is scheduled to transmit data to thereceiving node.

The transmitting network node transmits the data to the receiving nodeat block 606. The data transmission from the transmitting node to thereceiving node utilizes the allocated bandwidth and/or time slotsidentified in the transmission schedule received from the NC. Thetransmitting node may store a copy of the transmitted data in a computerreadable storage medium in the event that the data needs to beretransmitted to the receiving node.

At block 608, the transmitting node receives a second or subsequenttransmission schedule from the NC, and at decision block 610 thetransmitting node determines if the second or subsequent transmissionschedule includes reallocated bandwidth for retransmitting the data tothe receiving node. If the second or subsequent transmission scheduleincludes reallocated bandwidth for retransmitting the data, then thetransmitting network node may retrieve the data from memory and proceedto block 606 where it retransmits the data to the receiving networknode.

If the transmission schedule does not include reallocated bandwidth forretransmitting the data to the receiving network node, then thetransmitting node may proceed to block 610, where the data transmissionis completed and the transmitting network node may erase the previouslytransmitted data from the computer readable storage medium.

FIG. 7 is one example of a flow diagram for a method of acknowledgingdata transmission that may be performed by a receiving network node. Asshown in FIG. 7, the receiving node receives a transmission schedulefrom the NC at block 702. As described above, the transmission schedulemay identify bandwidth and/or time slots in which the receiving networknode is scheduled to receive data from a transmitting network node.

At block 704, the receiving network node receives the data from thetransmitting network node in accordance with the transmission scheduletransmitted by the NC at block 702. The receiving network node may storethe transmission schedule in a local computer readable storage mediumfor later use.

At decision block 706, the receiving network node determines if the datahas been successfully received from the transmitting network node. Thereceiving network node may determine if the data has been successfullyreceived by comparing the amount of received data, e.g., number of bits,bytes, etc., to an amount of data specified in the MAP packet byretrieving the MAP data from the computer readable storage medium. Insome embodiments, the transmitting node may add a cyclic redundancycheck (CRC) to the transmitted data, which may be used by the receivingnode to determine if an error occurred in receiving the data as will beunderstood by one skilled in the art.

If the data was successfully received, then the receiving node proceedsto block 708 and transmits an ACK message to the NC. At block 712, thedata transfer is completed and the received data is stored in a computerreadable storage medium.

If the data was not successfully received, then the receiving networknode transmits a NACK message to the NC at block 710. The receivingnetwork node then proceeds to block 702 and receives anothertransmission schedule allocating the bandwidth and/or time slots inwhich the data is to be transferred from the transmitting network nodeto the receiving network node from the NC. Accordingly, the method isrepeated until an ACK message is sent to the NC and the data transfer iscompleted at block 712.

The systems and methods described herein advantageously reduce theamount of bandwidth required to transmit acknowledgment messages in acoordinated network, which in turn increases the overall throughput ofthe network, compared to conventional systems and methods. Additionally,the improved systems and methods described herein reduces packet latencyand jitter compared to conventional systems and methods.

The methods described herein may be at least partially embodied in theform of computer-implemented processes and apparatus for practicingthose processes. The disclosed methods may also be at least partiallyembodied in the form of computer program code embodied in tangiblemachine readable storage media, such as random access memory (RAM), readonly memories (ROMs), CD-ROMs, DVD-ROMs, BD-ROMs, hard disk drives,flash memories, or any other machine-readable storage medium, wherein,when the computer program code is loaded into and executed by acomputer, the computer becomes an apparatus for practicing the method.The methods may also be at least partially embodied in the form ofcomputer program code, whether loaded into and/or executed by acomputer, such that, when the computer program code is loaded into andexecuted by a computer, the computer becomes an apparatus for practicingthe methods. When implemented on a general-purpose processor, thecomputer program code segments configure the processor to createspecific logic circuits. The methods may alternatively be at leastpartially embodied in a digital signal processor formed of applicationspecific integrated circuits for performing the methods.

Although the systems and methods have been described in terms ofexemplary embodiments, it is not limited thereto. Rather, the appendedclaims should be construed broadly, to include other variants andembodiments of the systems and methods, which may be made by thoseskilled in the art without departing from the scope and range ofequivalents of the systems and methods. Delimiters used in theclaims—such as ‘a)’ and ‘i)’—should not be taken as imputing any orderto the claims, but rather are provided only to serve as visual cues toadd in the parsing of the claims and as identifiers in the event that aparticular portion of the claim is to be later referenced.

1. A method, comprising: a) receiving a request for bandwidth from afirst network node of a coordinated network; b) broadcasting a firsttransmission schedule to a plurality of network nodes including thefirst network node, the first transmission schedule allocating bandwidthfor the first network node to transmit data to a second network node;and c) receiving an acknowledgement (ACK) message from the secondnetwork node, the ACK message identifying that the second network nodesuccessfully received the data from the first network node.
 2. Themethod of claim 1, wherein the ACK message is embedded within a requestfor bandwidth received from the second network node.
 3. The method ofclaim 1, further comprising: d) receiving a negative ACK (NACK) messagein a request for bandwidth from the second network node, the NACKmessage identifying that the data transmission from the first networknode to the second network node was not successful; and e) broadcastinga second transmission schedule to a plurality of network nodes includingthe first network node, the second transmission schedule reallocatingbandwidth for the first network node to retransmit the data to thesecond network node.
 4. The method of claim 3, wherein steps d) and e)are performed before step c).
 5. The method of claim 3, wherein thereallocated bandwidth in the second transmission schedule is the same asthe bandwidth allocated in the first transmission schedule, and whereinthe bandwidth is reallocated in response to receiving the NACK message.6. A network node, comprising: a receiver configured to receive arequest for bandwidth from a first network node of a coordinated networkand an acknowledgement (ACK) message from a second network node of thecoordinated network; a processor in data communication with thereceiver, the processor configured to generate a first transmissionschedule allocating bandwidth for the first network node to transmitdata to the second network node; and a transmitter in data communicationwith the processor, the transmitter configured to transmit the firsttransmission schedule to the first network node, wherein the ACK messageidentifies that the second network node successfully received the datatransmitted by the first network node during the allocated bandwidth. 7.The network node of claim 6, wherein the ACK message is embedded withina request for bandwidth received from the second network node.
 8. Thenetwork node of claim 6, wherein the receiver is configured to receive anegative ACK (NACK) message in a request for bandwidth from the secondnetwork node, the NACK message identifying that the data transmissionfrom the first network node to the second network node was notsuccessful, the processor is configured to generate a secondtransmission schedule including reallocated bandwidth for the firstnetwork node to retransmit the data to the second network node, and thetransmitter is configured to transmit the second transmission scheduleto the first network node.
 9. The network node of claim 8, wherein thereallocated bandwidth in the second transmission schedule is the same asthe bandwidth allocated in the first transmission schedule, and whereinthe bandwidth is reallocated in response to receiving the NACK message.10. A computer readable storage medium encoded with program code,wherein when the program code is executed by a processor, the processorperforms a method, the method comprising: a) receiving a request forbandwidth from a first network node of a coordinated network; b)broadcasting a first transmission schedule to a plurality of networknodes including the first network node, the first transmission scheduleallocating bandwidth for the first network node to transmit data to asecond network node; and c) receiving an acknowledgement (ACK) messagefrom the second network node, the ACK message identifying that thesecond network node successfully received the data from the firstnetwork node.
 11. The computer readable storage medium of claim 10,wherein the ACK message is embedded within a request for bandwidthreceived from the second network node.
 12. The computer readable storagemedium of claim 10, the method further comprising: d) receiving anegative ACK (NACK) message in a request for bandwidth from the secondnetwork node, the NACK message identifying that the data transmissionfrom the first network node to the second network node was notsuccessful; and e) broadcasting a second transmission schedule to aplurality of network nodes including the first network node, the secondtransmission schedule reallocating bandwidth for the first network nodeto retransmit the data to the second network node.
 13. The computerreadable storage medium of claim 12, wherein the reallocated bandwidthin the second transmission schedule is the same as the bandwidthallocated in the first transmission schedule, and wherein the bandwidthis reallocated in response to receiving the NACK message.
 14. Thecomputer readable storage medium of claim 12, wherein steps d) and e)are performed prior to step c).
 15. A method, comprising: a)transmitting a request for bandwidth to a network controller of acoordinated network, the request for bandwidth for transmitting data toa first node; b) receiving a first transmission schedule for each of aplurality of network nodes in the coordinated network from the networkcoordinator, the first transmission schedule allocating bandwidth fortransmitting the data to the first network node; and c) transmitting thedata to the first network node in the allocated bandwidth in accordancewith the first transmission schedule.
 16. The method of claim 15,further comprising: d) receiving a second transmission schedule for eachof the plurality of network nodes in the coordinated network from thenetwork controller, the second transmission schedule reallocatingbandwidth to retransmit the data to the first network node; and e)retransmitting the data to the first network node in the allocatedbandwidth in accordance with the second transmission schedule.
 17. Themethod of claim 16, wherein the reallocated bandwidth in the secondtransmission schedule is the same as the bandwidth allocated in thefirst transmission schedule.
 18. A network node, comprising: atransmitter configured to transmit a request for bandwidth to a networkcontroller and to transmit data to a first network node; and a receiverconfigured to receive a first transmission schedule from a networkcoordinator, the first transmission schedule allocating the bandwidth totransmit the data to the first network node, wherein the transmittertransmits the data to the first network node in accordance with theallocated bandwidth in the first transmission schedule received from thenetwork controller of the coordinated network.
 19. The network node ofclaim 18, wherein the receiver is configured to receive a secondtransmission schedule for each of the plurality of network nodes in thecoordinated network from the network controller, the second transmissionschedule reallocating bandwidth to retransmit the data to the firstnetwork node, and the transmitter is configured to retransmit the datato the first network node in the reallocated bandwidth in accordancewith the second transmission schedule.
 20. The network node of claim 19,wherein the reallocated bandwidth in the second transmission schedule isthe same as the bandwidth allocated in the first transmission schedule.21. A computer readable storage medium encoded with program code,wherein when the program code is executed by a processor, the processorperforms a method, the method comprising: a) transmitting a request forbandwidth to a network controller of a coordinated network, the requestfor bandwidth for transmitting data to a first network node; b)receiving a first transmission schedule for each of a plurality ofnetwork nodes in the coordinated network from the network coordinator,the first transmission schedule allocating the bandwidth to transmit thedata to the first network node; and c) transmitting the data to thefirst network node in the allocated bandwidth in accordance with thefirst transmission schedule.
 22. The computer readable storage medium ofclaim 21, the method further comprising: d) receiving a secondtransmission schedule for each of the plurality of nodes in thecoordinated network from the network controller, the second transmissionschedule reallocating the bandwidth to retransmit the data to the firstnetwork node; and e) retransmitting data to the first network node inthe reallocated bandwidth in accordance with the second transmissionschedule.
 23. The computer readable storage medium of claim 22, whereinthe reallocated bandwidth in the second transmission schedule is thesame as the bandwidth allocated in the first transmission schedule. 24.A method, comprising: a) receiving a first transmission schedule foreach of a plurality of network nodes in a coordinated network from anetwork coordinator, the first transmission schedule allocatingbandwidth for receiving data from a first network node; b) receiving thedata from the first network node in accordance with the firsttransmission schedule; and c) transmitting an acknowledgement (ACK)message to the network coordinator if the data is successfully receivedfrom the first network node.
 25. The method of claim 24, wherein the ACKmessage is included in a request for bandwidth.
 26. The method of claim24, further comprising: d) transmitting a negative ACK (NACK) message tothe network coordinator in a request for bandwidth if the data is notsuccessfully received from the first network node; e) receiving a secondtransmission schedule for each of the plurality of network nodes in thecoordinated network from the network coordinator, the secondtransmission schedule reallocating the bandwidth for receiving the datafrom the first network node; and f) receiving the data from the firstnetwork node in accordance with the second transmission schedule fromthe first network node.
 27. The method of claim 26, wherein thereallocated bandwidth in the second transmission schedule is the same asthe bandwidth allocated in the first transmission schedule.
 28. Themethod of claim 26, wherein the first and second transmission schedulesare media access plan (MAP) packets in a Multimedia over CoaxialAlliance (MoCA) network.
 29. The method of claim 26, wherein steps d),e), and f) are performed before step c).
 30. A network node, comprising:a receiver configured to receive a first transmission schedule from anetwork coordinator in a coordinated network, the first transmissionschedule allocating bandwidth for receiving data from a first networknode, and receive the data from the first network node in accordancewith the first transmission schedule; a processor in data communicationwith the receiver, the processor configured to determine if the data issuccessfully received from the first network node; and a transmitter indata communication with the processor, the transmitter configured totransmit an acknowledgement (ACK) message to the network coordinator ifthe processor determines the data is successfully received from thefirst network node.
 31. The network node of claim 30, wherein the ACKmessage is included in a request for bandwidth.
 32. The network node ofclaim 30, wherein the transmitter is configured to transmit a negativeACK (NACK) message in a request for bandwidth to the network coordinatorif the processor determines that the data is not successfully receivedfrom the first network node, and the receiver is configured to receive asecond transmission schedule from the network coordinator, the secondtransmission schedule reallocating the bandwidth for receiving the datafrom the first network node, and receive the data from the first networknode in accordance with the second transmission schedule.
 33. Thenetwork node of claim 32, wherein the reallocated bandwidth in thesecond transmission schedule is the same as the bandwidth allocated inthe first transmission schedule.
 34. The network node of claim 32,wherein the first and second transmission schedules are media accessplan (MAP) packets in a Multimedia over Coaxial Alliance (MoCA) network.35. A computer readable storage medium encoded with program code,wherein when the program code is executed by a processor, the processorperforms a method, the method comprising: a) receiving a firsttransmission schedule for each of a plurality of network nodes in acoordinated network from a network coordinator, the first transmissionschedule allocating bandwidth for receiving data from a first networknode; b) receiving the data from the first network node in accordancewith the first transmission schedule; and c) transmitting anacknowledgement (ACK) message to the network coordinator if the data issuccessfully received from the first network node.
 36. The computerreadable storage medium of claim 35, wherein the ACK message is includedin a request for bandwidth.
 37. The computer readable storage medium ofclaim 35, the method further comprising: d) transmitting a negative ACK(NACK) message to the network coordinator in a request for bandwidth ifthe data is not successfully received from the first network node; e)receiving a second transmission schedule for each of the plurality ofnetwork nodes in the coordinated network from the network coordinator,the second transmission schedule reallocating the bandwidth forreceiving the data from the first network node; and f) receiving thedata from the first network node in accordance with the secondtransmission schedule.
 38. The computer readable storage medium of claim37, wherein the reallocated bandwidth in the second transmissionschedule is the same as the bandwidth allocated in the firsttransmission schedule.
 39. The computer readable storage medium of claim37, wherein the first and second transmission schedules are media accessplan (MAP) packets in a Multimedia over Coaxial Alliance network. 40.The computer readable storage medium of claim 37, wherein steps d), e),and f) are performed before step c).